Infrastructure
Resolve the domain
Confirm that the hostname returns the intended A or AAAA address. For email problems, inspect MX and TXT records as well.
Open DNS Lookup →
Workflow · 10–15 minutes
Diagnose a website from the outside in.
A repeatable sequence that prevents you from debugging application code when the real problem is DNS, TLS or an unexpected redirect.
Security
Inspect the certificate
Check its validity window and names. A working DNS record does not guarantee that HTTPS is serving the right certificate.
Open SSL Checker →HTTP
Follow the redirect chain
Start with the exact URL users visit. Verify where every 301, 302, 307 or 308 sends them and remove unnecessary hops.
Open Redirect Checker →Response
Review HTTP and security headers
Confirm the final status and content type, then review browser protections such as HSTS and Content Security Policy.
Open Header Checker →Technical SEO
Check robots and sitemap discovery
Make sure both files are reachable before reviewing their actual directives, URLs and canonicalization choices.
Open Robots & Sitemap Checker →Start with the overview
Inspect a website